Valves are conventionally used in a number of applications to control the flow of fluids through piping systems. Traditionally in conventional check valves, including flap-type valves, ball valves, disc valves, and the like, the check valve is configured to allow flow in only one direction through the piping system. Such a check valve may allow fluid flow past the valve closure member in one direction while preventing fluid from flowing in the other direction, for example, toward a compressor or pump. In this way, check valves can be used to protect a compressor, pump, or other component from backwards flow or backwards pressure (backpressure).
In some applications, check valves are biased via a spring or other biasing mechanism. For example, “normally open” valves are biased open, requiring backpressure to close the valve and “normally closed” valves are biased closed, requiring forward pressure to open the valve. When either valve is operating correctly, the valve remains open while fluid is flowing through the valve in a forward direction, from an inlet to an outlet, and if the fluid flow reverses, the valve closes. This prevents flow in an unintended direction.
For both types of check valves, the valve may be installed in a plant or factory where the valve may not require replacement for the life of the plant or factory. However, to ensure safe operating conditions, there may be a desire to verify the operation of the check valve to ensure that the valve properly prevents backwards flow. Further, there may be regulatory requirements requiring periodic verification of proper operation. However, it is difficult or impractical to test a conventional check valve, since testing will often require either inducing backwards flow in the plant or factory or removing the valve, possibly requiring a significant halt in production.
Exercisable check valves do exist for which proper operation may be verified by testing. See, for example, U.S. Pat. No. 8,701,693.
However, there is a desire in the industry to enhance the ability to exercise a check valve to verify proper operation, such that a continuing need exists for a more efficient method and system to quickly and easily test the operation of a check valve without requiring significant additional clean up and without causing significant generation of waste.